This disclosure is directed generally to bypass valves for use in an aircraft environmental control system, and more specifically to pistons used in the bypass valves.
An environmental control system aboard an aircraft directs a portion of airflow for use in cabin air conditioning. A typical environmental control system will include bypass valves and temperature control valves to condition and control the airflow. Airflow bypassed for use in the cabin air conditioning systems can include particulate contaminates that can adversely affect bypass valve operation. Moreover, air bypassed into the air conditioning systems may include water that enters the bypass valve. Water and accumulated contaminates within the bypass valve can cause undesired operation of the bypass valve.
Furthermore, variations in temperature can induce stress in the components of the bypass valve, such as the piston. If the piston includes multiple parts, the variations in temperature experienced by the piston can cause thermally induced stresses in the joints and connections of the multiple parts of the piston. Over time, these thermally induced stress can cause the joints and connections of the multiple parts of the piston to fail.